This grant provides core support for a program on trace contaminants with special emphasis on heavy metals. Several interrelated research programs in environmental toxicolgy have grown to the point at which consolidation into a center offers clear scientific and administrative advantages. The center will provide core facilities in terms of analytical and histopathological laboratories and services in data processing, pharmacokinetics modeling and biomathematics. It will provide resources to develop embryonic research ideas to the point at which independent support may be obtained. The core faculty will provide long-term continuity of professional expertise and experience in the general field of environmental health science, will provide a national resource to respond to urgent needs in its field, and will provide training for new professionals in the field. The research in the center will be restricted to those trace contaminants most likely to affect human health. In the immediate future, the center will concentrate on the toxic heavy metals (Cd, Hg and Pb), in continuation of well-established projects at Rochester. Since multiple exposures (e.g., dietary methylmercury and selenium from pelagic fish) also occur, the interaction of heavy metals with other substances will be studied as well. The center will pursue a coordinated program of studies on exposed human populations, on volunteers, and laboratory animals. This program has drawn support in the past, and will continue to draw support from virtually all the classical disciplines available in the medical center.